The Laigin, modern spelling Laighin (Irish
pronunciation: [ˈl̪ˠaːjɪnʲ]), were a population group of
early Ireland. They gave their name to the province of Leinster, which
in the medieval era was known in Irish as Cóiced Laigen, meaning
"province of the Leinstermen".[1] Their territory, located in
south-east Ireland, is thought to have once extended from the River
Shannon to the River Boyne.[1]

Etymology[edit]
Laigin is a plural noun, indicating an ethnonym rather than a
geographic term;[2] however the Irish system of naming territories
meant that an area tended to be named after an apical ancestor-figure
even when the ruling dynasty had no links to that figure.[3] The
origin of their name is uncertain; however, it is traditionally
assumed to derive from the Irish word láigen, meaning 'a spear'.[1]
Early texts use names Láigen and Gáileoin interchangeably.[4]
Origins[edit]
The
Laigin are claimed as being descended from Labraid Loingsech.[1]
Modern historians suggest, on the basis of Irish traditions and
related place names, that the
Laigin were a group of invaders from
Gaul or Britain, who arrived no later than the 6th century BC, and
were later incorporated into the medieval genealogical scheme which
made all the ruling groups of early
IrelandIreland descend from Míl
Espáine. Placenames also suggest they once had a presence in north
Munster and in Connacht.[5]
Related peoples and dynasties[edit]
Archaic poems found in medieval genealogical texts distinguish three
groups making up the Laigin: the
Laigin proper, the Gáilióin, and
the Fir Domnann. The latter are suggested to be related to the British
Dumnonii.[1][6]
Amongst others, some of the dynasties that claimed to belong to the
Laigin include: Uí Failge, Uí Biarrche, Uí Dúnlainge, Uí
Ceinnselaig, Uí Garrchon, and the Uí Máil.[1]
In medieval literature[edit]
In the legendary tales of the Ulster Cycle, the king of the Connachta,
Ailill mac Máta, is said to belong to the Laigin. This is thought by
Byrne (2001) to be related to a possible early domination of the
province of Connacht by peoples related to the Laigin, the Fir Domnann
and the Gamanrad.
See also[edit]

Dublin Castle administration
Parliament of
IrelandIreland (
Irish House of LordsIrish House of Lords and Irish House of
Commons)
Privy Council of Ireland
Four CourtsFour Courts (King's Bench, Exchequer, Chancery and Common Pleas)
Court of Castle Chamber
Peerage of Ireland
Army
Church of Ireland
Grand Lodge of Ireland
Trinity College, Dublin
Order of St Patrick
Jacobites
Whigs
Tories
Irish Patriots
Defenders
Orangism
United Irishmen